Elastomeric materials are utilized in numerous industrial application articles, for example in myriad molded shapes, belts, hoses. Molded elastomers can be bonded to reinforcing members such as metallic materials with such common devices including dampers and mounts which provide vibration control, e.g., engine mounts. In many applications, the elastomer article is often exposed to oils, fuels, or other degrading substances. Many conventional vulcanized elastomeric materials typically tend to degrade when exposed to petroleum-based products. Most vulcanized elastomers which exhibit resistance to petroleum based products also exhibit poor fatigue resistance. There has been a continuing search within the elastomer industry to develop an elastomer which is both resistant to degrading chemicals and resistant to fatigue.
One method of rendering elastomeric materials resistant to degrading chemicals is to apply a protective coating. However, when these oil-resistant coatings have been applied to flexible elastomeric substrates such as natural rubber or polybutadiene, the elastomers suffer from poor fatigue resistance and poor adhesion to the natural rubber or polybutadiene substrate, manifested as cracking, separation from the elastomer and a breach of the coating.
U.S. Pat. No. 5,621,042 discloses an isocyanate modified fluoroolefin-vinyl ether copolymer resin. The fluoroolefin-vinyl ether copolymer resins do not exhibit elastic rebound at 100% elongation without deformation and would not be suitable for coating flexible elastomeric substrates like rubber according to the present invention.
U.S. Pat. No. 4,395,462 discloses a coating for silicone elastomers derived from a peroxide-curable fluoroelastomer gum composition which contains (1) an epoxide compound in an amount sufficient to react with the acidic by-products generated during curing of the elastomer, and (2) an organic peroxide in an amount sufficient to achieve curing of the fluoroelastomer gum at elevated temperatures.
There is an unmet need for a fluoroelastomer coating that can be applied to non-oil-resistant elastomers such as the various non-fluorinated elastomers NR, PBD, SPR, EPDM, BUTYL, CHLOROPRENE, types, etc. The need exists to provide a protective coating that has improved durability, flex-fatigue resistance as well as fuel and solvent resistance which can be applied and cured without the need for subjecting the vulcanized article to additional heat-curing.